1. Field of the Invention
The present invention relates to a system and method for defining a window to search a region of interest in an image. It also relates to a system disposing of means capable of implementing this method as well as a method for determining a visibility distance in foggy weather.
A preferred application of the invention is the field of automotive equipment, in particular for detecting visibility distance in foggy weather.
2. Description of the Related Art
With the development of electronic technologies, sensors and means of processing, numerous improvements have been proposed to make driving vehicles more safe or comfortable. Some of these improvements rely on analyzing an image of the environment around the vehicle in order to adapt handling of the vehicle or to inform the driver. Such is the case with systems for determining a visibility distance. These systems in particular are directed to adjusting the lighting of the vehicle according to the visibility distance.
In the known way, these systems include acquisition of an image and determination of a region of interest in this image, intended to be processed in real time. Determination of a region of interest aims to limit the area of the image which is the object of the processing and consequently to reduce the quantity of data to be processed. This enables the time and resources required for processing to be reduced. It also allows elements of the image which would disturb its processing to be excluded.
Determining a region of interest traditionally implies the definition of a search window inside which the region of interest is then determined. In existing technologies, the search window is a simple vertical band crossing the image according to its height and laterally delimited by two vertical rectilinear edges.
It is easy to understand that the definition of the search window directly impacts the field forming the region of interest and thus the extent and quality of the digital processing, such that optimization of the definition of the search window is an important part of the overall processing.
What is needed, therefore, is an improved system and method for improving optimizing the definition of the search window.